.test{
    background-image:url(../images/myimage/tip.png)!important;
}
.icon-expand-all {
    background-image: url(../images/myimage/expand-all.gif) !important;
}
.icon-collapse-all {
    background-image: url(../images/myimage/collapse-all.gif) !important;
}

.icon-tree{
    background-image:url(../images/myimage/tree.png)!important;
}

.icon-form{
    background-image:url(../images/myimage/form.png)!important;
}